import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str;
        while (in.hasNextLine()) {
            str = in.nextLine();
            char[] chars = str.toCharArray();
            char[] chars2 = new char[chars.length];
            int k = 0;
            for (int i = 0; i < chars.length; i++) {
                if (chars[i] != ' ') {
                    boolean bool = true;
                    for (int j = 0; j < chars2.length; j++) {
                        if (chars2[j] == chars[i]) {
                            bool = false;
                            break;
                        }
                    }
                    if (bool == true) {
                        chars2[k] = chars[i];
                    }
                    k++;
                }
            }
            for (int i = 0; i < chars2.length; i++) {
                System.out.print(chars2[i]);
            }
        }
    }
}